Method of continuously tin plating ferrous metal stock



April 29, 1941.

J. S. NACHTMAN METHOD OF CONTINUOUSLY TIN PLATING FERROUS METAL STOCKFiled March 30, 1937 8 Sheets-Sheet l J. S. NACHTMAN April 29, 1941.

METHOD 0? CONTINUOUSLY TIN PLATING FERROUS METAL STOCK Filed larch 30.1937 8 Sheets-Sheet 2 April 29, 1941. J. s. NACHTMAN 2,240,265 METHOD OFCONTINUOUSLY L'IN PLATING FERROUS METAL STOCK 8 Sheets-Sheet 3 Filedlarch 30, 1937 April ,1 J. s. NACHTMAN 2,240,265

- METHOD OF CONTINUOUSLY TIN PLATING FERROUS METAL STOCK Filed larch 30.1957 8 Sheets-Sheet 4 J. S. NACHTMAN April 29, 1941.

METHOD Of CONTINUOUSLY TIN PLATING FERROUSMETAL STOCK 8 Sheets-Sheet 6Filed March 30, 1937 R, U I I I IHHI I I I IUIHU HHIHI IH IHHHI I I IHHHHU HHHH IUHHI I I IU U r I I HHI M HH IH IUHHH IU $8 J. S. NACHTMAN Aplil 2.9, 1941.

METHOD OF CONTINUOUSLY TIN PLATING FERROUS METAL STOCK Filed Iarch 30.1937 8 Sheets-Sheet 7 April 1941- J. s. NACHTMAN 2,240,265

- METHOD OF CONTINUOUSLY TIN PLATING FERROUS METAL STOCK Filed March 30,1937 8 Sheets-Sheet 8 Patented Apr. 29, 1941 METHOD OF CONTINUOUSLY TINPLATING FERROUS METAL STOCK John S. Nachtman, Beaver, Pa.

Application March 30, 1937, Serial No. 133,911

5 Claims.

This invention relates to process and apparatus for producing metalstock coated with dissimilar metal, and particularly to process andapparatus for continuously coating sheet and the like ferrous metalstock with tin whereby sheets, strips and the like of indefinite lengthmay be produced continuously in finished marketable form.

The invention is designed, primarily, to produce tin-plated ferrousmetal stock or strip. Reference may be made to my copending applicationsSerial Nos. 126,529 and 127,776, filed February 18, 1937, and February25, 1937, respectively.

The method of tin-plating ferrous metal stock for the practice of whichthe apparatus of the invention is particularly designed, includes thefollowing steps, viz.: providing a continuous supply of stock byattaching, preferably by welding,

the end of a fresh strip to the end of an exhausted strip, adjusting thefeed of the strip in such a manner, preferably by means of a loopingslack-producer, that continuous passage of the strip through subsequentstages of treatment in the apparatus may be continued during the periodwhen the end of an exhausting strip is held stationary for welding to itthe end of a fresh strip, cleaning the stock by passingit throughappropriate cleaning and degreasifying baths of electrolytic or otherappropriate forms, scrubbing the stock by means of appropriate brushingmechanism, rinsing and pickling the stock with subsequent scrubbing,electroplating the stock with subsequent scrubbing, rinsing and dryingthe stock, alloying, cleaning and bumi shing the stock, and finallycoiling or otherwise appropriately preparing it for removal andhandling. In the apparatus as illustrated in the drawings, and ashereinafter more particularly described, the cleaning of the stock,before its subjection to the plating operation, is accomplished in tanksin which electrolytic cleaning is not resorted to. However, electrolyticcleaning may be resorted to as a substitute or supplement.

Furthermore, the alloying and burmshmg operations as hereinafterdisclosed are conducted with greater facility, and in a more economicalmanner than has heretofore been possible, at the same time furnishing aproduct superior in quality and uniformity, and the various elements orunits of the apparatus, whereby the steps of the plating methodareaccomplished, are designed, arranged and coordinated to most effectivelyattain these objects, so that the sequential steps of the method maybeperformed cbntinuously, and the product continuously discharged, asdistinguished from apparatus of similar types wherein the stock must berepeatedly handled for transfer from apparatus for performing certainmethod steps upon it to other apparatus for performing subsequent stepsof the method.

In other words, when the metal stock is continuously fed into theapparatus of the invention, its passage therethrough for subjection toand treatment in accordance with the various method steps may beuninterrupted, while at the same time subject to inspection as desired,and

by means of baths 'of hot and cold oil, but an furnace of the reducingatmosphere gyp g d its adjuncts, may be employed for this purpose.

The apparatus of the invention is designed, as hereinbefore indicated,for continuous operation, whereby, as a specific example, tin-coatedferrous metal strip, preferably steel strip, wire or sheet,

' 'may be produced by an electroplating process the product may becontinuously discharged.

The invention comprises apparatus for continuously coating (preferablyelectroplating) metal stock in strips, wire or sheets of indefinitelength, including, in combination, means for supporting metal stock tobe fed into the apparatus, means for joining the end of one piece ofstock to another to produce a continuous strip, means providing for thestopping of the end of the strip during the joining operation, while thebalance of the strip continuesto move through the apparatus, means forcleaning, pickling, scrubbing, rinsing, plating, drying, alloying andburnishing the stock, and finally cleaning, rinsing, drying anddischarging the finished plated product, means for properly guiding andtensioning the strip during its travel, and in various novel featuresinherent in the means referred to, all as will be pointed out moreparticularly hereinafter and finally claimed.

In the accompanying 'drawings illustrating the invention, in the severalfigures of which like parts are similarly designated,

Figures 1a, 1b and 10, when placed end to end in order, illustrate,send-diagrammatically, a preferred embodiment of the complete apparatusof the invention.

Fig. 2 is an enlarged side elevation of the payout end of the machine,including the pay-out blocks, feed table, welding mechanism, squeegeeand clamp of the invention.

Fig.3 isa plan view of some of the parts 11-- lustrated in Fig. 2.

Fig. 4 is an enlarged side elevation of the slack-producer and itsassociated clamp.

Fig. 5 is an enlarged side elevation of a scrubbing unit, bridle-stand.a fragment of an electroplating tank, and an interposed dancer roll.

Fig. 6 is an enlarged fragmentary side elevation of an electroplatingapparatus of preferred form, as shown in Fig. 1b, and particularlyadapted to the plating of relatively light (thin) stock.

Figs. 7a, 7b and 7c illustrate, on a large scale, the two end portionsand a part of theintermediate portion of an electroplating tank of atype particularly adapted for the plating of relatively heavy (thick)stock, Fig. 70 showing the provision of a squeegee for the stock as itleaves the tank. 1

Fig. 8 is an enlarged fragmentary sectional elevation illustrating thehot oil tank, the cold oil tank, and the power-drivensqueegees and rollassociated therewith.

Fig. 9 illustrates a modification of the arrangement of the hotoil tankand the cold oil tank. a Fig. 10 illustrates a further modification ofburnishing apparatus, including a cold air blast means in place ofthecold oil tank, associated with a hot oil tank, and

Fig. 11 illustrates polishing mechanism similar to the scrubbingmechanism of Fig. 5, but appropriately modified.

The pay-out device A of the machine includes a foundation member, bed orbase I provided with bearings 2 and 2 in which are rotatably mountedsimilar shafts 3 and 3 respectively, provided with overhangingextensions 4 and 4' of expansible type upon which may be mounted reels 5carrying the coiled strips of stock S to be subjected to theelectroplating process. "These reels are clamped upon the extensions 4and 4' by virtue of their expansible nature and may be locked in placethereon, if desired, by plates 6 and 6'. Hence, as the stock iswithdrawn from the reels, and the reels thereby rotated, the shafts 3and 3' will turn with them. In order that rotation of the reels may beretarded so that proper tension may be maintained upon the unwindingstock, the

shafts 3 and 3' are provided with brake drums I and 'l', with whichcooperate brake shoes 8 and 8' carried by arms 9 and 9' to which areapplied adjustable weights l0 and I0, respectively.

It will be obvious that one of the reels 5, and the stock carriedthereby, may be held in reserve while stock is unwound from the otherreel, and that when stock is exhausted from such other reel, and the endof such stock leaves the reel, the stock on the first-mentioned orreserve reel may be fed into the apparatus and joined to the end of thestock just exhausted, as will be explained in detail hereinafter.

Each of the reel-carrying extensions 4, 4', has located adjacent to it aguide roller Ii carried on a shaft l2 mounted in brackets l3 arrangedupon the bed or base i, and these rollers II are thus so arranged thatthe stock may pass over them as it leaves the reels 5, and be supportedby them and guided to a hold-down roller I4 arranged adjacent to a tableI 5 providing a support upon which the stock may readily be handled, andfurnished with a guide or fence l6 by means of which proper alignment ofthe stoc may be insured.

At the opposite end of the table I5 is arranged the welding apparatus Bcomprising a supporting block l1 and a welding head I8, and these partsare supported upona stand l9, and are so designed as to produce,transversely of the overlapped ends of the pieces of stock a pluralityof spot welds whereby such ends may be Joined to 1 provide an unbrokenstrip of stock for passage through the succeeding elements or units ofthe apparatus.

In order that, subsequent to the welding operation, the strip of stockmay be aligned and tensioned, a pressure device or squeegee C isprovided including a fixed roller 20 and a movable roller 2!, both ofwhich are preferably made of rubber. and the latter of which is carriedby a frame 22 slidable on supports 23 and subject'to pressure exerted bysprings the compression of which may, as desired, be regulated byadjustable stops 2!.

As will appear from the previous discussion, the stock or strip ispreferably handled in such a manner that it is at all timessubstantially continuously and uninterruptedly moved past the varioustreating positions. That is, in accordance with my invention, themovement of the strip along the electroplating line will be carried outas before even while the trailing end of one coil or strip is beingwelded to the leading end of a new strip coil. To this end theslack-producer D is provided (see particularly Fig. 4). Thisslack-producer operates in conjunction with an appropriate clamp Epreferably comprising clamping blocks 28 and 21 responsive in operationto the energizing and de-energizing of a solenoid controlled by theoperator during the welding operation, and functioning to immovablyclamp the exhausting end of a strip of stock while the operation ofwelding the end of a reserve strip thereto is being performed.

As shown, the slack-producer D comprises a as to accommodate loops ofstock aggregating over feet in length, and it includes threestationariiy mounted rollers 29, 30 and 3! and two movably mountedrollers 32 and 33 over which the strip of stock is passed back andforth, as shown, to produce the desired extended loops. The rollers 32and 33 are mounted in an elevator carriage 34 travelling in verticalguides 35 and connected by a cable 36 with hoisting mechanism includinga motor and gearing 31 and a brake 38. Obviously, when the elevatorcarriage 34 is at the top of its shaft the loops in the strip of stockwill be extended to the limit, and therefore the greatest amount ofslack will be produced in the strip. Now, when the strip is clamped bythe clamp E at one end, and the body of the strip is still travellingthroughout the apparatus, the elevator "carriage 34 will descend topermit such travel, and the slack originally produced is such thatbefore the carriage 34 reaches the lower limit of its travel the weldingoperation referred to will have been completed. Upon the completion ofthe welding operation and the release of the clamp E, the elevatorcarriage will again be hoisted to the upper limit of its movement, andadditional slack will be produced in the strip of stock in preparationfor a subsequent welding operation. Of course, the framework 28 will bebuilt of a height suilicient to accommodate any extent of slack to dnecessary.

As the strip of took S leaves the slack-producer, it is engaged by therollers of a squeegee C substantially similar in construction andfunction to the squeegee C, and the stock passes thence into a cleaningtank F in which it is cleansed, degreasified and partially prepared forplating. In the embodiment shown, the cleaning tank F is a bridle standJ (see Fig. including feed rolls such that cleaning by the use of anordinary solution, by saponification, emulsiflcation or the like, may beresorted'to, and it is preferably a steel tank lined with rubber.However, see my copending application No. 127,776, electrolytic cleaningmay be-resorted to at this stage, and in such case an electrolyticcleaner of any desired type may be employed, the electrolyte being suchas will satisfy the cleaning requirements without unduly attacking thestock.

The cleaning tank F is preferably provided with rollers 39 which holdthe stock submerged in the cleaning fluid, and with a roller 46arranged.

which obnoxious vapors and fumes may be removed, and the inspectiondoors are provided at suitable intervals in the hood, one of same beinglocated adjacent to the elevated roller 40.

Upon passing from the cleaning tank F, the strip S is operated upon by ascrubbing-mechanism G (see particularly Fig. 1a, and compare Figs. 1band 5) including reciprocating rotary brushes 44 and 44' arranged forcontact with the opposite faces of the strip S, and rubber or othersuitable rollers 45 and 45' arranged toback up the strip in alignmentwith the brushes 4 and 44'. Appropriate pressure may be applied to thebrushes 44, 44' by any appropriate means (not shown) controlled by thehandrwheels 46, 45'. As shown in the drawings (see Figs. 1a, 1b and 5)of the scrubbing mechanisms G, G and G, the strip S in moving across theback up rollers 45 and 45 passes in slightly arcuate paths so that firstone convex arcuate surface on one side and then another convex arcuatesurface on the other side of the strip is brushed by the brushes l4 andH, The reciprocation and rotation of the brushes may be imparted to themby any suitable means (not shown) power-driven by a suitable motor ll.Included in combination with the scrubbing mechanism G is a squeegee 48somewhat similar in construction to the squeegees C and C However, aspreviously described, squeegees C and C work on dry strip and provide atension on the strip, while the squeegees 48 work on wet strip and thusprevent carrying over of the cleaning solution. Water is sprayed uponboth sides of the strip S as it passes through the scrubbing mechanism,by any appropriate spray device or the like, not shown.

Upon leaving the scrubbing mechanism G, the strip of stock passes into arinse tank H wherein it is held beneath the surface of the rinse waterby a roller 49. Fresh water is constantly fed to this rinse tank and itmay, if desired, be heated by a steam coil or other appropriate means.Moreover, a spray of water is preferably directed upon the strip, as itemerges from the tank H and passes therefrom over the roller 50 into thepickle tank I. This pickle tank is provided with rollers 5| which holdthe strip submerged in a pickling liquid of a character and strengthsuitable to the final stage of preparation of the strip for theelectroplating operation. The rinse tank H and pickle tank I arepreferably covered by a hood 52 having substantially the same characterand function as the hood previously described.

Opon leaving the pickle tank I, the strip of stock is subjected toanother scrubbing operation by a scrubbing mechanism G similar to thescrubbing mechanism G, and it passes thence to 53 and 5| geared togetheras indicated at 55 and a pressure roll 56 to which appropriate pressureis applied by springs 51 the compression of which may be regulated by asuitable screw 58. Chain and sprocket gearing 59, 60, 6| supplies apower drive from the motor 62 and gear box 63 to the shaft 65 of theroller 53, and thence through the gearing 55 to the roll 54. Thepressure roll 56 furnishes friction between the roll 54 and the strip Sadequate for feeding of the strip under the influence of the drivedescribed. This bridle stand is shown as furnishing the initial feed ofthe strip S through the preceding units of the apparatus, but if desiredthe squeegees C and C and any of the rolls in the tanks F, H and I andin the scrubbing mechanisms G and G may be power operated toadditionally drive the strip. If the squeegees C and C are poweroperated, their motors will act as previously explained to providetension on the strip.

As the strip S leaves the bridle stand J it passes over a guide roller65 and thence to a weighted dancer roll 66 operating in a well orguideway 61 and functioning to maintain a proper tension upon the stripafter it leaves the bridle stand.

The strip next passes into the electroplating tank. This electroplatingtank may take a variety of forms, but those best suited to the apparatusas a whole are illustrated particularly in Figs, 1b and 6 and in Figs.7a, 7b, 7c, respectively.

It is to be noted that the provision of the bridle stand J and dancerroll 56 just prior to the point of entrance of the strip S into theelectroplating tank makes it possible for the strip to enter the tankunder no appreciable tension, and that this lack of tension maintainsthroughout the passage of the strip through the tank, thus guardingagainst the occurrence of wavy edges in the strip and the necessity forfinally rolling the strip to restore it to its original desired flatform.

The electroplating tank K of Figs. 1b and 6 is best suited to thehandling of relatively light (thin) stock, whereas the electroplatingtank of Figs. 7a, 7b, 7c is best suited to handle relatively heavy(thick) stock. When the stock is light it may easily be looped asillustrated in Figs'. lb

and 6, but when it is relatively heavy it does not lend itself soreadily to this looping, being more easily and effectively handled bysubstantially continuous horizontal passage. Obviously, the

type of electroplating tank illustrated in Figs.

rollers 69, some of which latter may be power-- driven, if desired, at aspeed in sychronism with the predetermined speed of travel of the stockS,' and the stock is looped upon these rollers, as

shown, and thus subjected to electrolytic action in the tank. Aplurality of anodes l0 vertically suspended within thetank by a bus bar(not shown) are connected withthe positive side of a source of current,preferably one or more motor generator sets, and the strip of stock Sbecomes the cathode by virtue of connection of an appropriate number ofthe rollers 69 with the negacontrolled by means of electricallyenergised heatingrodssuch as'low diifusicnOalrodslLandasanaidtomaintainingdesiredtemperatureof the oil, the tankmay beprovidedwith asectional In the type of electroplating tank illustratedin Figs. 7a, 7b, 7c, the anodes II are supported horizontally uponsuitable hangers '(not shown) and the strip of stock 8passeshorizontally between them and beneath guide rollers II betweenwhich latter it is, at appropriate intervals, looped upwardly forpassage over conductor rollers 14. The anodes I2 and the conductorrollers I4 are connected, respectively, with the positive and negativesides of the source of current in substantially the same manner as inthe form of electroplating tank illustrated in Figs. 1b and 6,

appropriate brush and commutator means II being provided for the contactrollers 14.

In both forms of electroplating tanks illustrated, the number of contactrollers 69 and 14 which may be connected to the source of current isdependent upon the ampere capacity of such source and thecharacteristicsiof the coating or plating desired. I

As indicated, the strip of stock is subjected to the action of asqueegee C as it leaves the eleccover composed of slabs or plates 02.

Issuing from the hot oil tank through a narrow slot or shield member1,108 Figs. 1b, 1c, 8, and 9, that prevents transfer. of the oil, theplated stock enters a cold oil tank qin which it is subjected to thecooling and brightening action'of cold oil circulatedin the tank bymeans of a circulation pump (not shown) having its intake connection atIt and its discharge con-- nection at II, II, in a member or non-ls llenclosing a portionof the strip and the oil against both sides thereof.Since, as shown, the lower part of the entrance side (hot oil side) ofthe member 88 has a higher elevation than an upper part of the member onits discharge side (cold oil side), a static balance is obtained betweenthe hot and cold oil chambers; also, eddy currents such as due to athermo-siphon action between the hot and cold oil are prevented. The hotoil tank and the cold oil tank are surmounted by a hood I! similar tothe hoods previously referred to.

, troplating tank, whether the tank be of the form illustrated in Figs.lb and 6, or that illustrated in Figs. 7a, 7b and 7c, and excess ofelectrolyte thereby removed.

The plated or coated stock is now subjected to the action of a scrubbingmachine (3 similar to the scrubbing mechanisms G and G and passes thenceinto a rinse tank L, provided with a hood I6 and a squeegee C and thento a hot air drier M.

The hot air drier M, in the form shown, comprises merely a housing 71with a hot air intake 78 supplied by any appropriate means not shown,and furnished with a fan is. It will be understood that this type of hotair drier is merely illustrative, and that the plated stock may beelectrically or otherwise heated to dry it, if desired. The function ofthis hot air drying is to preheat and completely dry the plated stock.

After leaving the drier M, the plated stock is subjected to thetensiohing action of a dancer roll 00, to some extent similar to thatpreviously described, and passes thence through a hot oil tank N inwhich the oil is maintained at a temtemplated by the invention of myapplication Serial No. 127,776, hereinbefore referred to, the tinplating is deposited upon a preliminary plating of copper, nickel,chromium or other appropriate metal or alloy, then the action of the hotoil bath will be to melt and alloy the outer coating of tin with theunder coating of dissimilar metal to produce an impervious and brilliantfinish.

As illustrated particularly in Fig. 8, the oil is heated and itstemperature thermostatically Instead of forming the hot and cold oiltanks N and 0, respectively, as two separate units connected by a slotmember II, they may be formed as a unitary structure divided into twocompartments N and 0', see Figure 9, for the hot and cold oil,respectively, by. a heat-insulating partition 83' suitably sheathed asindicated at 83". Inasmuch as the cold oil is constantly circulated, andthus cooled, by way of the intake 84 and discharge means 8 l, thetemperature will be maintained between and I". and the flow of the oilwill thus govern the temperature in the casing of the apparatus.

It will be noted that the construction of the hot and cold oil tanks,whether of the form illustrated in Fig. 8 or in Fig. 9, is such thatvery little transfer of oil from one tank to the other can take place,the principle of the apparatus being that of a'U-tube, whereby thespecific gravity of the oil in one tank holds the oil in the other tankin balance.

In place of the oil, a salt solution may be used in the hot bath.

In passing from the cold oil'tank O, the plated, annealed and burnishedstock is subjected to the action of a roller 88 and squeegees C and 0,all of which are power driven, preferably by chain and sprocket gearing,as shown, from a motor 88 and a gear box 00. The power driven roll 88and squeegees C and C serve not only to remove from the plated stocksurplus oil adhering to it,

and which might otherwise 'be carried out of the oil tank 0, but tomaintain considerable tension upon the strip as it passes through theoil tanks, and to drive it on its way to the other units of theapparatus.

As illustrated in Fig. 10, the cold oil tank may be dispensed with. andas. a substitute therefor blast or jet means T may be provided wherebycold dry air may be projected against both sides of the strip.

Instead of employing the oil baths just described at this stage of theprocess, the alloying and brightening of the strip may be accomplishedby means of a reducing atmosphere furnace, thus dispensing with thecleaning apparatus, hereinafter referred to, made necessary by theemployment of the hot and cold oil tanks.

When a furnace is employed for the purpose of alloying the coating, itmay be supplemented by water spray devices operating upon the strip asit emerges from the furnace, and the strip may thereafter be burnishedby a machine including rotating and reciprocating bumishing rollsfurnished with surfaces composed of steel wool, glass wool, brass wool,or other appropriate similar substances.

Also, if desired, the spray means may be omitted and the plated stripburnished hot, as it comes from the furnace, by the burnishing rolls.

The burnishing machine may be constructed in a manner similar to thescrubbing mechanisms G, G G hereinbefore referred to, substantially asillustrated in .Fig. 11, wherein the rotating and reciprocating rolls 44and 44' are shown as provided with metallic wool facings .44".

When the oil treatment is not resorted to, and the furnace, sprays andburnisher used instead, the subsequent cleaning and drying apparatus P,P Q, L L and M hereinafter specifically referred to, may be omitted, andthe finished stock, as it comes from the burnishing machine of Fig. 11led to the bridle stand J and wind-up R.

However, the oil treatment of the plated stock is included in thepreferred embodiment of the apparatus herein disclosed as it produces amost lustrous finish and is considered most desirable for the continuousoperation intended.

Moreover, if desired, after the strip of stock has been plated, scrubbedand rinsed, a wind-up may be employed, and 9. terminus established atthis point in the process for which the apparatus is intended.Thereafter brightening and alloying of the plated strip may beaccomplished by either the oil treatment or furnace treatment as aseparate operation. Inasmuch, however, as the apparatus herein disclosedis designed for the purpose of treating the stock in such a manner as tocontinuously produce, from the original strip, a completed productsubjected in the apparatus to the various steps of an appropriateelectroplating process, without interruption, the complete apparatuseither in the form illustrated, or with such modifications as thosereferred to for making possible the inclusion of additional steps in theprocess, is deemed to be the most satisfactory and efficient embodimentof the invention.

From the squeegees C and C the strip S passes through a cleaning tank P,squeegee C and rinse'tank P, which tanks are similar in function andoperation to the tanks F and H, respectively, hereinbefore described, toan electrolytic cleaning tank Q. In .rthis electrolytic cleaning tank,the strip S is supported and guided in its passage by metal rolls 9|,which give it a charge of electricity and conduct it between oppositely.

charged iron grids 92. The electrolyte may be of any appropriatecharacter which will not, under the influence of electric current,injure the coating or plating of the strip, but will function merely toremove from it any grease, oil and fatty substances carried over by it.The electrolyte may be continuously circulated in the tank Q by anyappropriate means, not shown.

After leaving the electrolytic cleaning tank Q, the strip passes througha squeegee C to rinse tanks L and L similar in function and operation tothe rinse tank L, and thence through a squeegee C, a hot airdrier M orits equivalent, as explained in connection with the hot drier M, whenceit is led to a bridle stand J 1 similar to the bridle stand J butdriven, in combination with a windup mechanism R by an electric motor 93and appropriate gearing. The tanks P, P Q, L and IF are provided withhoods 94, 95 and 96,'respectively, similar to those previouslydescribed, for collecting and carrying off vapors and fumes.

The wind-up mechanism includes guide rollers I 91 and 98 which may be,used for guiding the finished strip to reels 99 and!!! respectively,whereby as one reel is filled with the finished strip, the strip may besevered and its severed end led to the other reel to continue thewinding, thus providing for removal and replacement of the filled reel.The reels of the wind-up mechanism are preferably similar to those ofthe payout A, and interchangeable therewith, the shafts upon which thereels of the wind-up mechanism are mounted being substantially similarin construction and mode of operation to the shafts 3', 4' of thepay-out A but equipped with friction clutches operated by the motordrive to compensate for gradually increasing size of the wound strip;the drive, generally, being synchronized with the travel of the stripthrough the apparatus.

Obviously if, as hereinbefore indicated, it is desired to deposit uponthe strip a preliminary coating or plating of a metal or alloy prior toplating with tin the electroplating tank by which such preliminarycoating or plating is deposited, should be followed in the apparatus byappropriate scrubbing and rinsing means.

Furthermore, should it be desired to dispense with alloying andbrightening of the coated or plated strip, the terminus or wind-up ofthe apparatus would follow the scrubbing, rinsing and drying apparatuswhich operate upon the strip subsequent to its passage through theelectroplating means. Although for the purpose of simas sheets, etc.;the base metal shape'or strip preferably has some characteristics offlexibility. Various changes and modifications, other than and inaddition to those specifically referred to,

are considered to be within the spirit of the invention and the scope ofthe following claims.

I claim:

1. In a method of making a bright tin electroplated continuous metalstrip, the steps of wet mechanically cleaning the surfaces of acontinuously moving tensioned strip by passing the strip in slightlyarcuate paths, brushing under pressure first one convex arcuate surfaceon one side and then another convex arcuate surface on the other side ofthe continuously moving tensioned strip, maintaining said arcuatesurfaces by backing up the strip against the brushing elements, andspraying the strip while brushing; then immediately passing the stripinto an electrolyte and electroplating the continuously moving stripwith tin, then removing electrolyte from the continuously movingelectroplated strip surfaces, and brightening the continuously movingelectroplated surfaces by subjecting the same to a medium maintained ata temperature sufiicient to alloy the tin with the strip; continuouslymoving and tensioning the strip during said mechanical cleaning,electroplating, electrolyte removing, and brightening steps by applyingdirect propulsive power to said strip at a plurality of steps; theapplying of 'said propulsive power serving to control the tension on thecontinuously moving strip during each of said steps.

2. The method as defined in claim 1 in which a reduced tension ismaintained on the strip as it passes through the electroplating step..

3. The method as defined in claim l-in which the treatment following theelectroplating step includes wet mechanically brushing the surfaces ofthe continuously moving electroplated strip by passing the strip undertension in slightly arcuate paths, brushing under pressure first oneconvex arcuate surface on one side and then another convex arcuatesurface on the other side of the continuously moving tensioned strip,maintaining said arcuate surfaces by backing up the strip against thebrushing elements, and spraying the strip while brushing.

4. The method as-deflned in claim 1 in which the brightening treatmentfollowing the electroplating step includes immersing the continuouslymoving tensioned strip in a hot oil bath for heating the electroplatedmaterial to a temperature sumcient to melt the same and alloy it withthe strip metal body. and then immediately cooling the heatedelectroplated continuously moving tensioned strip to provide brightenedelectroplated surfaces. v

5. The method as defined in claim 1 inwhieh the brightening treatmentfollowing the electroplating step includes heating the electroplatedmaterial in a reducing atmosphere furnace to a temperature sumcient toalloy it with the strip metal body and then passing the strip undertension while hot in slightly arcuate paths, bumishing under pressurefirst one convex arcuate surface on one side and then another convexarcuate surface on the other side of the continuously moving tensionedstrip, and maintaining said arcuate surfaces by backing up the stripagainst the burnishing elements.

JOHN S. NACH'IMAN.

